The insert contains the following restriction sites (approximate kb from the end upstream of ccrA): HindIII--4.3, KpnI--4.8. The latter site interrupts the gene.

The vector is a derivative of pMK16 deleted for the carboxy terminal half of the tetR marker and has had the small EcoRI/BamHI fragment replaced with the MCS-containing EcoRI/BamHI fragment from plink 322.